Kougekiryoku Kyokuburi no Saikyou Majutsushi ~Kinryokuchi 9999 no Daikenshi, Tensei shite Nidome no Jinsei wo Ayumu~

Uranus, the strongest great warrior, was the leader of the Hero Party which saved the world from Demon King. 300 years later, he reincarnated as Egil Schwein while keeping his previous status of 9999 strength. Deciding to become a court magician in his new life, he enrolls at the Hero Academy which was established to train the next generation of heroes. Thereupon, he gets entangled one after another with his classmates who are beautiful girls...!